An electrical machine, in particular a canned electric motor, has a stator and a rotor, which are in electrodynamic interaction, whereby the rotor is driven. For example, the canned electric motor is used to drive a turbo compressor or a rotary pump. If the conveyance media of the turbo compressor or the rotary pump are appropriately cold, they can be used for cooling the canned electric motor. Cooling the rotor using a processing gas and the stator using a processing liquid is known. The canned electric motor has a can, which extends cylindrically around the rotor and thus hermetically separates the rotor from the stator, so that the processing gas can wash around the rotor and the processing liquid can wash around the stator. In order to prevent disadvantageous eddy current losses in the can, which would reduce the efficiency of the canned electric motor, the can is produced from an electrically nonconductive material. However, the presence of the can results in a gap enlargement between the rotor and the stator, whereby the efficiency of the canned electric motor is decreased. It would therefore be desirable to make the can as thin-walled as possible, whereby the strength of the can is reduced, however. This is problematic in particular if the cooling media for the rotor and the stator have high pressure differences and/or high temperature differences, so that, for example, in corresponding applications, a maximum permissible buckling strength of the can could be exceeded.
An electric medium frequency motor having a liquid-flooded stator is known from EP 1 271 747 A1, which is separated by a can from the rotor, which
is mounted liquid-tight in bearing flanges. The can has a greater thickness on two side parts than on a middle part, whereby the side parts have a higher thermal conductivity than the middle part and contact the bearing flanges on both sides in a formfitting and removable manner.
An electric motor which is water-cooled in the stator chamber and air-cooled in the rotor chamber is known from DE 41 38 268 A1, in which the cooling water washes directly around the windings located in the stator grooves. The stator sheet assembly is delimited toward the rotor chamber by pressure-resistant inner housing wall faces, which absorb the bearing forces of the roller-bearing-mounted rotor shaft.